A car has become an indispensable traffic means among people living in the modern society. Various types of in-car audio/visual (AV) devices have been constantly developed and introduced into the market to satisfy most consumers' requirement for comfortable life. Meanwhile, computers have also become indispensable among people in their work and interaction with others. In response to different requirements in different occasions, differently configured computers have been widely developed. Among others, a computer for mounting and using in a car and adapted to combine with other in-car AV devices has drawn the attention of related manufacturers and dealers.
However, the car computer is subjected to the following limits in its applications:    1. The car computer has a supply voltage different from that of the general portable computers. This voltage problem can be overcome through electronic circuit designs.    2. Special care must be taken to maintain and control the power supply to the car computer. To prevent the continuously operating car computer from consuming the battery power of the car and accordingly, adversely affecting the normal operation of the car, the car computer must be set to be turned on only when the car power source is ON, i.e., when the car has been started, and to automatically close the operating system when the car power source is OFF. However, the currently available Windows does not allow a user to shut down a computer by arbitrarily powering off the computer. Therefore, it is an important issue for a car computer to automatically control the power supply thereof to ON or OFF according to the on or off of the car power source.
It is therefore tried by the inventor to develop a power control system for car computer, so as to overcome the past limits to the application of a car computer.